Tremendous volumes of soil worldwide are contaminated with hazardous materials, such as, for example, oil-derived hydrocarbons, and heavy metals, to name just a few examples. Soil remediation is a process by which the soil may be treated in order to reduce the level of hazardous materials in the soil. Large sums of money are spent on soil remediation.
There are numerous approaches for remediating contaminated soils. Representative approaches include, but are not limited to, biological treatment to biologically alter the hazardous materials, air stripping to strip the hazardous materials from the soil with air, soil washing to wash the contaminants from the soil, solvent extraction to extract the contaminants from the soil with a solvent, vitrification in which the contaminates are locked into the soil with vitrification, vacuum extraction in which a vacuum is used to extract the contaminants from the soil, and thermal desorption in which heat is used to thermally desorb the contaminants from the soil. The approaches may be performed either in-situ or else soil may be excavated and transported to a treatment facility.
However, there are known disadvantages associated with each of these approaches. For example, biological treatment may tend to be relatively specific for certain contaminants and may face challenges when mixed contaminants are present in the soil. Air stripping and vacuum extraction may be relatively ineffective when the contaminants have low volatility. Vitrification may tend to be challenging when the soil has flammable materials and may tend to be costly in operation and capital cost. Soil washing and solvent extraction tend to consume large volumes of water or solvent which then need to be processed and may tend to be expensive. Thermal desorption may tend to be expensive and energy intensive.
Thus there is a general need in the art for new and useful hazardous material treatment methods.